Add files for react.js
Add files for jQuery
Set up stub for extension
Add support for parsing github diff
Split layout of code into modules
Get side by side rendering logic working
Get show more lines working
Get side by side mode working
Add backbone and underscore js libraries
Large rewrite to use backbone model with react.js views
Fix bug with line numbers not showing in side by side mode
Make settings checkboxes work
Make side by side diffs work
Add styling for diff viewer
Hacks to make changing modes (inline, side-by-side) work

The problem is probably with react's algorithm for DOM manipulation.
The hack for now is to just completely replace the view (i.e. remove
view from DOM) with a new view. This suffers in terms of performance,
but works for now.

Another problem is `componentWillMount()` doesn't always seem to be
called on CheckboxesView so changing to a `componentDidMount()` for
now, which seems to work so far...
Add lookup cache by cid for Backbone models of each type
Fix error about not using keys for array of components

Fixing this error also eliminated earlier bug with text area of
some comments not showing up when toggling mode.
Make replying to existing comment work
Replace return false w/ event.preventDefault() (react.js warning)
Make adding new comment work in side-by-side view